The present application is generally in the field of microneedle patches for the transport of therapeutic or biological molecules into the skin or across tissue barriers.
Transdermal drug delivery provides several advantages over other routes for administering a drug formulation to a patient. One method for transdermal drug delivery involves using microneedle arrays to bypass the barrier properties of the stratum corneum. Although microneedle arrays were first reported over 15 years ago, numerous obstacles have prolonged the development of microneedle arrays and delayed its commercialization. For example, the small size of the microneedles makes verifying effective administration of the therapeutic agents difficult. Many groups have looked to use of applicators and other types of special insertion devices that are used to apply a pre-set force that will ensure that the microneedles penetrate the stratum corneum. These applicators and other insertion devices, however, can be cumbersome to use and unnecessarily increase the cost of using the microneedle arrays.
For example, most microneedle systems under development either have separate, complex applicators or integrated applicators. The separate, complex applicators are used to handle and apply microneedle patches to the patients and can be burdensome to the user, bulky, costly for single use applications, and/or non-ideal for multi-person administration (e.g., mass vaccinations) due to cross-contamination issues. The integrated applicators are integrated into the microneedle devices themselves and become wearable systems that must be worn for the duration of the required wear time, which adds an undesirable level of 3-dimensionality to a wearable patch/device.
Other problems that have been difficult to overcome have included the scale-up of consistent and reliable methods of manufacture of microneedle arrays, development of highly concentrated and stable therapeutic agents that can be effectively administered using microneedle arrays, and cost effective systems for protecting the microneedles after manufacture until their use.
Thus, there remains a need for simple, effective, and economically desirable devices for transdermal administration of a variety of drug types to a patient.